vbox: pull vboxHostDeviceGetXMLDesc out from vboxDomainGetXMLDesc

The USB-related code in vboxDomainGetXMLDesc is deeply nested and
difficult to add new code. So flatten it. To do so, the code is
pulled out from vboxDomainGetXMLDesc to make the function short
and to leaverage early return and goto for error handling.
Signed-off-by: NRyota Ozaki <ozaki.ryota@gmail.com>

src/vbox/vbox_tmpl.c

@@ -2206,6 +2206,102 @@ vboxDomainGetMaxVcpus(virDomainPtr dom)
                                          VIR_DOMAIN_VCPU_MAXIMUM));
 }
 
+static void vboxHostDeviceGetXMLDesc(vboxGlobalData *data, virDomainDefPtr def, IMachine *machine)
+{
+    IUSBController *USBController = NULL;
+    PRBool enabled = PR_FALSE;
+    vboxArray deviceFilters = VBOX_ARRAY_INITIALIZER;
+    size_t i;
+    PRUint32 USBFilterCount = 0;
+
+    def->nhostdevs = 0;
+    machine->vtbl->GetUSBController(machine, &USBController);
+
+    if (!USBController)
+        return;
+
+    USBController->vtbl->GetEnabled(USBController, &enabled);
+    if (!enabled)
+        goto release_controller;
+
+    vboxArrayGet(&deviceFilters, USBController,
+                 USBController->vtbl->GetDeviceFilters);
+
+    if (deviceFilters.count <= 0)
+        goto release_filters;
+
+    /* check if the filters are active and then only
+     * alloc mem and set def->nhostdevs
+     */
+
+    for (i = 0; i < deviceFilters.count; i++) {
+        PRBool active = PR_FALSE;
+        IUSBDeviceFilter *deviceFilter = deviceFilters.items[i];
+
+        deviceFilter->vtbl->GetActive(deviceFilter, &active);
+        if (active) {
+            def->nhostdevs++;
+        }
+    }
+
+    if (def->nhostdevs == 0)
+        goto release_filters;
+
+    /* Alloc mem needed for the filters now */
+    if (VIR_ALLOC_N(def->hostdevs, def->nhostdevs) < 0)
+        goto release_filters;
+
+    for (i = 0; (USBFilterCount < def->nhostdevs) || (i < deviceFilters.count); i++) {
+        PRBool active                  = PR_FALSE;
+        IUSBDeviceFilter *deviceFilter = deviceFilters.items[i];
+        PRUnichar *vendorIdUtf16       = NULL;
+        char *vendorIdUtf8             = NULL;
+        unsigned vendorId              = 0;
+        PRUnichar *productIdUtf16      = NULL;
+        char *productIdUtf8            = NULL;
+        unsigned productId             = 0;
+        char *endptr                   = NULL;
+
+        deviceFilter->vtbl->GetActive(deviceFilter, &active);
+        if (!active)
+            continue;
+
+        def->hostdevs[USBFilterCount] = virDomainHostdevDefAlloc();
+        if (!def->hostdevs[USBFilterCount])
+            continue;
+
+        def->hostdevs[USBFilterCount]->mode =
+            VIR_DOMAIN_HOSTDEV_MODE_SUBSYS;
+        def->hostdevs[USBFilterCount]->source.subsys.type =
+            VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB;
+
+        deviceFilter->vtbl->GetVendorId(deviceFilter, &vendorIdUtf16);
+        deviceFilter->vtbl->GetProductId(deviceFilter, &productIdUtf16);
+
+        VBOX_UTF16_TO_UTF8(vendorIdUtf16, &vendorIdUtf8);
+        VBOX_UTF16_TO_UTF8(productIdUtf16, &productIdUtf8);
+
+        vendorId  = strtol(vendorIdUtf8, &endptr, 16);
+        productId = strtol(productIdUtf8, &endptr, 16);
+
+        def->hostdevs[USBFilterCount]->source.subsys.u.usb.vendor  = vendorId;
+        def->hostdevs[USBFilterCount]->source.subsys.u.usb.product = productId;
+
+        VBOX_UTF16_FREE(vendorIdUtf16);
+        VBOX_UTF8_FREE(vendorIdUtf8);
+
+        VBOX_UTF16_FREE(productIdUtf16);
+        VBOX_UTF8_FREE(productIdUtf8);
+
+        USBFilterCount++;
+    }
+
+release_filters:
+    vboxArrayRelease(&deviceFilters);
+release_controller:
+    VBOX_RELEASE(USBController);
+}
+
 static char *vboxDomainGetXMLDesc(virDomainPtr dom, unsigned int flags) {
     VBOX_OBJECT_CHECK(dom->conn, char *, NULL);
     virDomainDefPtr def  = NULL;
@@ -2236,7 +2332,6 @@ static char *vboxDomainGetXMLDesc(virDomainPtr dom, unsigned int flags) {
             PRUint32 netAdpCnt                  = 0;
             PRUint32 netAdpIncCnt               = 0;
             PRUint32 maxMemorySize              = 4 * 1024;
-            PRUint32 USBFilterCount             = 0;
             PRUint32 maxBootPosition            = 0;
             PRUint32 serialPortCount            = 0;
             PRUint32 serialPortIncCount         = 0;
@@ -2261,7 +2356,6 @@ static char *vboxDomainGetXMLDesc(virDomainPtr dom, unsigned int flags) {
             IVRDEServer *VRDxServer             = NULL;
 #endif /* VBOX_API_VERSION >= 4000 */
             IAudioAdapter *audioAdapter         = NULL;
-            IUSBController *USBController       = NULL;
 #if VBOX_API_VERSION >= 4001
             PRUint32 chipsetType                = ChipsetType_Null;
 #endif /* VBOX_API_VERSION >= 4001 */
@@ -3296,90 +3390,7 @@ sharedFoldersCleanup:
             }
 
             /* dump USB devices/filters if active */
-            def->nhostdevs = 0;
-            machine->vtbl->GetUSBController(machine, &USBController);
-            if (USBController) {
-                PRBool enabled = PR_FALSE;
-
-                USBController->vtbl->GetEnabled(USBController, &enabled);
-                if (enabled) {
-                    vboxArray deviceFilters = VBOX_ARRAY_INITIALIZER;
-
-                    vboxArrayGet(&deviceFilters, USBController,
-                                 USBController->vtbl->GetDeviceFilters);
-
-                    if (deviceFilters.count > 0) {
-
-                        /* check if the filters are active and then only
-                         * alloc mem and set def->nhostdevs
-                         */
-
-                        for (i = 0; i < deviceFilters.count; i++) {
-                            PRBool active = PR_FALSE;
-                            IUSBDeviceFilter *deviceFilter = deviceFilters.items[i];
-
-                            deviceFilter->vtbl->GetActive(deviceFilter, &active);
-                            if (active) {
-                                def->nhostdevs++;
-                            }
-                        }
-
-                        if (def->nhostdevs > 0) {
-                            /* Alloc mem needed for the filters now */
-                            if (VIR_ALLOC_N(def->hostdevs, def->nhostdevs) >= 0) {
-
-                                for (i = 0; (USBFilterCount < def->nhostdevs) || (i < deviceFilters.count); i++) {
-                                    PRBool active = PR_FALSE;
-                                    IUSBDeviceFilter *deviceFilter = deviceFilters.items[i];
-
-                                    deviceFilter->vtbl->GetActive(deviceFilter, &active);
-                                    if (active) {
-                                        def->hostdevs[USBFilterCount] = virDomainHostdevDefAlloc();
-                                        if (def->hostdevs[USBFilterCount]) {
-                                            PRUnichar *vendorIdUtf16  = NULL;
-                                            char *vendorIdUtf8        = NULL;
-                                            unsigned vendorId         = 0;
-                                            PRUnichar *productIdUtf16 = NULL;
-                                            char *productIdUtf8       = NULL;
-                                            unsigned productId        = 0;
-                                            char *endptr              = NULL;
-
-                                            def->hostdevs[USBFilterCount]->mode =
-                                                VIR_DOMAIN_HOSTDEV_MODE_SUBSYS;
-                                            def->hostdevs[USBFilterCount]->source.subsys.type =
-                                                VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB;
-
-                                            deviceFilter->vtbl->GetVendorId(deviceFilter, &vendorIdUtf16);
-                                            deviceFilter->vtbl->GetProductId(deviceFilter, &productIdUtf16);
-
-                                            VBOX_UTF16_TO_UTF8(vendorIdUtf16, &vendorIdUtf8);
-                                            VBOX_UTF16_TO_UTF8(productIdUtf16, &productIdUtf8);
-
-                                            vendorId  = strtol(vendorIdUtf8, &endptr, 16);
-                                            productId = strtol(productIdUtf8, &endptr, 16);
-
-                                            def->hostdevs[USBFilterCount]->source.subsys.u.usb.vendor  = vendorId;
-                                            def->hostdevs[USBFilterCount]->source.subsys.u.usb.product = productId;
-
-                                            VBOX_UTF16_FREE(vendorIdUtf16);
-                                            VBOX_UTF8_FREE(vendorIdUtf8);
-
-                                            VBOX_UTF16_FREE(productIdUtf16);
-                                            VBOX_UTF8_FREE(productIdUtf8);
-
-                                            USBFilterCount++;
-                                        }
-                                    }
-                                }
-                            }
-                        }
-                    }
-
-                    /* Cleanup */
-                    vboxArrayRelease(&deviceFilters);
-                }
-                VBOX_RELEASE(USBController);
-            }
+            vboxHostDeviceGetXMLDesc(data, def, machine);
 
             /* all done so set gotAllABoutDef and pass def to virDomainDefFormat
              * to generate XML for it